Gellab is a computer based system of analysis of sets of 2D gels. It incorporates sophisticated subsystems such as statistical, data base manipulation, image acquisition, etc. It has been applied to a variety of experimental systems in which quantitative changes in one or more proteins among hundreds or thousands of unaltered proteins is the basic analytic problem. During the year numerous extensions to the armamentarium of procedures available to the user have been developed. It has also been applied to several new problems involving both early and late cellular differentiation and or protein synthesis. The objective of defining an exportable version of GELLAB (one that will run on a reasonably powerful microcomputer-affordable by a university department) is being actively pursued.